[If you cannot see the flash video below, you can click here for a high quality mp4 video.]
Interviewee: Dr. Ana Maria Cuervo, The Albert Einstein College of Medicine
It’s a Dirty Job…
Cellular biologist Ana Maria Cuervo and colleague Cong Zhang hold two tiny old white mice that look very much alike. But one of the mice has a liver that looks and functions like that of a very young mouse; the Albert Einstein College of Medicine researchers have found a way to stop age-related decline in an entire organ.
Cuervo says that, just like us, mice accumulate damage to their cells as they grow old, which eventually leads to toxic protein buildup she calls “garbage.” One of the ways cells keep clean is with the help of internal surveillance systems that detect and clean out this cellular refuse. Cuervo and Zhang have given some of these mice an extra copy of the gene that produces these internal garbage detectors, and in this study, they targeted the cells of the liver.
“The most exciting finding is that, when we compare the cells from the young animals to the old animals, we normally find garbage, accumulation of damage, but when we compare this with our animals in which we have added this extra copy of this gene, we found that the cells were clean,” says Cuervo.
Cuervo explains that when mice reach middle age, their cells’ cleaning systems start slowing down, so she decided to turn on the extra gene when the mice reached middle age in order to prevent this decline. When the researchers found that the cells were clean they knew they were on the right track, but wanted to see if the cells and the entire liver functioned better.
Liver function tests showed that the modified old mice did just as well as mice one quarter their age.
“By removing these damaged products, by maintaining the cleaning systems inside the cells, we were able to preserve the function of a whole organ. So if we can do that in the whole body, we hope that we will be able to have very healthy animals and, of course, we’d like to have healthy people even more than healthy animals,” says Cuervo, who is also a physician.
A chief source of cellular protein damage is oxidation, which occurs in all cells of our bodies. The “internal garbage detectors” Cuervo targeted are actually antennae-like structures on organelles called lysosomes, which grab onto damaged proteins and pull them inside the lysosome so they can be broken down and recycled.
“Even the typical reactions that you have in your body produce oxidation or damage of proteins, sort of like proteins getting rusty. And your cells eliminate these rusty proteins, and this is what guarantees that your cells work properly and don’t accumulate any kind of garbage,” explains Cuervo.
But Cuervo does not think gene therapy for the elderly is the answer. She hopes to find compounds that can mimic the results of gene therapy. She is also studying how modified diets can help keep organ function high.
Ultimately, Cuervo would like to try the same strategies to delay age-related brain disorders like Parkinson’s disease and Alzheimer’s disease. She points out that people who develop Alzheimer’s disease don’t show symptoms until later in life which could indicate that as people age their brain cells are not able to clean themselves.
When asked if the same strategy can be used to keep skin from looking old, she laughs and says her own mother was proud of her work on keeping organs young, but seemed more curious about skin.
“Maybe there is hope for all of us with wrinkles,” she says with a twinkle in her eyes.
PUBLICATION: Nature Medicine, online early August 10, 2008
RESEARCH FUNDING: National Institute on Aging, National Institute of Diabetes and Digestive and Kidney Diseases, an Ellison Medical Foundation Award and a Glenn Foundation Award
Share on Facebook |
Tweet This |